Alkylaryl sulfonate-hydroxyethyl-cellulose detergent composition



July 8, 1952 L. R. BACON Er AL I ALKYLARYL SULFONATE-HYDROXYETHYLCELLULOSE DETERGENT COMPOSITION Filed Jan. 5, 1949 o n o. QN on oe A om n 8 mw o om om oo mm mm om om o om om m 91. om om o. om a. OO- m o.. m, A m\ om. W MM.. um S ///Q A/////// Y w /SHE/MM//mf ANN ,\VV\ om. o2 oom Leslie R.Bc|con, Clifton E .Sm||h, Thomas H.Vau ghn, INV EN TORS Patented July 8, 1952 Artur orifice ALKYLARYL SULFONATE-HYDROXYETHYL- CELLULO SE DETVERGENT COMPOSITION .Leslie R. vBacon `and .Clifton E. Smith, *Wyandotta and ,Thomas H. Vaughn, Grosse 11e, lMich., asvsigners to vWyandotte Chemicals Corporation,V Wyandotte, Mich., a corporationlof Michiganv Application January 5, 1949, Serial No. 69,252

yl Claims l The present invention relates to a detergent composition'based on an .alkylaryl sulionate and a detergent promoter or accelerator addition thereto consisting of hydroxyethylcellulose. Hydroxyethylcellulose isA alternatively known vin chemical terminology as"glyco1 cellulose orthe ethylene glycol ether of cellulose." We have discovered, that in order to obtain `the desired detergency accelerating effect, that the water.- soluble hydroxyethylcellulose -should be vpresent in the-amount of 1-6`3% byweight and preferably,

The syntheticdetergent employedconforms to the general type formula: R-fp-SOs--Na where R is an alkyl group having 9-l6carbon atoms, derived from a `petrolenm hydrocarbon distillate boiling 'in the rangeof 150e3o0 C., and `is an aromatic V`hydrocarbon `group of the @benzene family.

Itvhas of course previouslyY-beenknown to add various water-soluble, thickening y and dispersing agents to synthetic detergents. We have determined however, -after `careful andv exhaustive investigation, that the action of these thickening and dispersing agents `vis Vextremely specific and selective. When such an agent Will produce an increase in detersive action with one particular synthetic detergent, it will oftentimes actually decrease -the detergency of another. Various thickening and dispersing agents which have heretofore been addedto synthetic detergents are glues, gums, starches, pectin, albumin, and cellulose ethers. Methyl cellulose,.carboxymethylcel-lulose, hydroxyethylcellulose and hydroxypropylcellulose are examples of the latter. .In the case of'sulfonated synthetic detergents, .such as employed in the composition ot our invention, ,and

particularly in the caselof sodium kerylbenzene sulfonatal starch, Irish moss, methyl cellulose and hydroxypropylcellulose, for Yexample, feit-her reduce the detergency, or vatrbest, produce only I a minor degree of detergency promotion, Car- 1 Sodium kerylbenzene sulfonate-isan alkylaryl sulfonate derived from a petroleum hydrocarbon distillate boiling in the kerosene range and benzene.

No. 677,034, died-June 15, 194.6, now Patent No. 2,568,334, issuedfSept. 18,1951.

Previous enorts involving theuseof-hydroxyethylcellulose,v have been directed towardv -the composition formulation in which a syntheticgde.- tergent such as a sodium .alkyl vsulfonate .or ,an allfrylpherlOl-ethylene oxide condensation prod.- uct (cf. UyS. Patent No. 2;,33531950, is 4prent in a .minor proportion, lviz.;r, 10,-; 1-l,0% fby Weight, and the hydroxyethylcellulose `'Ls present-in lina-jor proportion, viz. 7u-90% by-weight. Here again, the detergency promotion 'is A.only slight,.onfthe order of 10..-15 %'improven ient-and ineffective for all practical purposes, particularly Vwhen Ait `is .desired to use the detergent'composition in competition and substitutionfor soapinlaundering cot.-

ton fabrics. f

In brief, Vfor practical laundry washinarsynthetic detergent composition -mustzhave detersive properties equal to or vbetter than-.that of Soap, if it is to be a commercially ,acceptable product. The detergent properties :(as measured by the carbon .soil removal tests .asihereinafter described in detail) of the synthetic detergent vcomposition should be promotedlor accelerated to v.at least or more of.standard i=in.order .Ltoibe commensurate with-those of a rvhgflrgrade soap. On the other hand, and for less exacting washing operations, it is necessary even :then `to #obtain an appreciable increase indetergency,'Suchas a promotion to 130% `.of standard, :ifthev vadded effort and expenseof the promoting .agent .isgto be justified. f I

We have discovered that the .addition .of..5-57 of hydroxyethylcellulose to the alkylaryl sulfonates :0f .the general type iormulahereinabove given, e. g. sodium kerylbenzene-sulfgnateproduces an increase ,in detergent .properties to 15.0- of standard; y,and that the additionfof 1-63% 0f hydrDXyethylQellulose produces `Aanincrease to'1,30,% orgreateroflstandard. Y

The alkylarylzsulfonate ingredient oithecomposition of o ur inventiomas,previously indicated, is derived fromfthe `alkylationof,anaromatic l'iydrocarbon,y of :the benzene family, .suchasbenzene, toluene, xylene. VSuchralkylation maybe elected by the Friedel-Crafts cndensation of -a chlorinated petroleum n.hydrocarbon distillate having 9=16 -carbon atoms vlboil'ing in `vthe #ra-nge of 15G-300. C., with. the.' benzenoid Lhydrocarbn;

or the direct condensation of an unsaturated petroleum hydrocarbon of 9-16 carbon atoms with benzene, or its homologues. The resultant alkylaryl hydrocarbon is then sulfonated to form alkylaryl sulfonic acids which are subsequently neutralized, such as by means of caustic soda, to form the water-soluble alkylaryl sulfonates. During such neutralization step, excess sulfuric acid present in the alkylaryl sulfonic acid mixture is neutralized to an inorganic salt, such as sodium su1.

fate. Therlatter -is customarily,. and in a commercial' alkylaryl sulfonate detergent product, permitted to remain and in some instances might even be increased by external addition. A proportion of about 60% sodium sulfate is usually found to be present in commercially available alkylaryl sulfonate type of synthetic detergents. Whether pure (i. e. sulfate-free) alkylaryl sulfonate or the built (NazSOi-containing) type is employed, the improved results of the composition of our invention are equally Well obtained. The terms alkylaryl sulfonate and sodium kerylbenzene sulfonate when generally or more broadly employed hereinafter, in both the description and claims, shall be regarded as including both the sulfate-free and sulfate-containing forms of this ingredient of our compositions. Specific identification will of course be made of the respective forms where conciseness or particularization so requires.

The .other ingredient of the composition of our invention is hydroxyethylcellulose or ethylene glycol ether of cellulose. The number of ethylene glycol residue groups (CH2OHCH2-O) per glucose unit of cellulose in such hydroxyethylcellulose is dependent on the alkalinity of the solution in which it istoV be employed. Generally, the number of-glycol residue groups varies inversely as the alkalinity of the aqueous solution in which the composiiton is to be used. Thus. in approximately neutral aqueous solution, the hydroxyethylcellulose should. contain 2-3 glycol residue groups per glucose unit of cellulose; whereas irl-'solutions of above 10 pH, 1-2 glycol residue groups per glucose unit of cellulose are `suilicien't.

Inasmuch as it is not presently possible to determine precisely by analytical methods the proportion of hydroxyethyl groups substituted per glucose unit of cellulose (otherwise referred to as -degree of substitution) the specication herein of number of glycol residue groups per glucose unit of cellulose is given on the theoretically calculated basis.

The detergent. properties heretofore referred to, and subsequently to be referred to in this description, were determined by the following test procedure:

SOIL REMOVAL TEST PROCEDURE A standard soiled cotton fabric is first prepared as follows:

Fourteen pieces. of a standard muslin (Indian Head muslin 53 x. 47, 5.15 oz. per sq. yd. manufactured by Nashua Mfg. Co.) are definished or pre-treated in order to remove the sizing or finish and to shrink the material, by a treatment with caustic soda solution, followed by a Wash with sodium stearate, which is then followed by a number of rinses with soft water. The water used in this operation is softened to below one grain CaCO: equivalent toa gallon. Following such pre-treating operation, the muslin is extracted for minutes and tumbled to dryness in a commercial gas-heated laundry dryer.

The denished standard muslin, cut in pieces measuring 101/2 x 36" are placed in a Monel metal wash wheel containing an emulsion of colloidal carbon black and water-soluble mineral coil. After thorough impregation of the standard muslin in the carbon black and oil emulsion, it is removed piece by piece and passed once without folding through a power-driven household type wringer to squeeze out any residual aqueous dispersion, the wringer pressure being so adjusted asA toleave in the cloth an amount of standard -oil solution equal to i1% of the dry weight of cloth. The standard soiled muslin or test cloth is then dried and cut into test pieces measuring 21/2" x 31/2". Before actual use of the so-prepared standard soiled cloth, it is given a final check by the following described carbon soil removal test in a standard detergent solution, and over a range of several solution concentrations.

To evaluate the soil removal characteristics of synthetic detergent compositions, 0.25% by Weight solutions of the composition to be tested are prepared in distilled water and 100 ml. portions of such solution are added to each of 10 one-pint jars of a Launder-O-Meter (type 12Q-EF-SPA, manufactured by Atlas Electric Devices Company) standard laundry test machine.

Fifteen ll diameter stainless steel balls are placed in each jar, after which two pieces of the previously prepared standard soiled cloth are added to each of nine jars. In the tenth jar are placed two pieces of unsoiled but pre-treated cloth and this latter jar serves as a blank for determining the turbidity of the detergent solution. The so-prepared jars, heated to a temperature of i2 F. in a constant temperature bath are then placed in the Launder-O-Meter" and run for 10 minutes at a speed of 42:1 R. P. M. The jars are then removed from the test machine and replaced in the constant temperature bath. The contents of each lar to which the standard soiled cloth has been added are poured through a coarse screen to separate the steel balls and the standard soiled cloth from the soil suspension which is collected in a large beaker. The composite suspension thus attained is mixed thoroughly and a sample placed in a l0 mm. light absorption cell. The light absorption of this composite solution, as well as the light absorption of the solution in the tenth or blank jar containing` the unsoiled cloth test pieces is then measured (by a Fisher Electrophotometer). By means of a calibration curve for the Fisher Electrophotometer, such curve being'constructed by obtaining light absorption values of known quantities of carbon black dispersion added to distilledwater, the carbon soil removal value sought (in mg. of carbon per liter of solution) is obtained by taking the difference between the converted values of the light absorption of the composite solution or suspension from the nine jars and of the light absorption of the suspension in the blank jar. y

The soil removal values are then reported as a percentage of that of a standard detergent solution used as a reference' or control material; viz: by dividing the mg. of carbon removal value of the test material composition by the mg. of carbon removal value for Vthe standard or control detergent solution which is determined concurrently in the same test run and on the same standard soiled test cloth, and multiplying by 100. i

a'co'zgrei As mentioned at theioutsetof this description, it was found `that the detergency promoting action of hydroxyethylcellulose was extremely unpredictable, when applied to varying types of detergent compounds. The following Table I sets forth the resultswhich were obtained by the above described carbon soil removal test procedure whenapplied to several diierent types of synthetic detergents or surface active agents, and also high kgrade (or high titer) soap, in the proportion of parts of hydroxyethylcellulose per 100 parts of detergent. These tests were conducted in distilled water at 140 F. and at a uniform detergent concentration of 0.25%. In each case, the increase in carbon soil removal value is given as the per cent increase over the corresponding value of the particular detergent with no hydroxyethylcellulose present.

t will be noted from the foregoing table, that in the case of the several distinct vtypes, of surface active agents or detergents, namely nonionic, sodium soap and Quaternary ammonium compounds, that only a slight promoting or boosting effect was obtained. On the other hand, in the case of the alkyl-aryl sulfonate type of detergent, namely the sodium kerylbenzene sulfonate, a highly effective increase in detergency of 64%, was obtained.

The unique and unexpected ability of hydroxyethylcellulose to promote the detergent properties of sodium kerylbenzene sulfonate is further emphasized by the following vtest results where various other cellulose ethers and thickening agents were combined with sodium kerylbenzene sulfonate. These results are given in the following Table 11. These tests were similarly conducted in distilled water at 140 F., at a uniform sodium kerylbenzene sulfonate concentration oi 0.25%. The detergency Values are given in per cent of standard, the standard of course being the sodium kerylbenzene sulfonate alonewith no additive agent present.

The above results not only substantiate the outstanding detergency promoting powers of hydroxyethylcellulose, but they also are of a surprisingnature in .that they `:reveal fa very closely homologous .cellulose ether., ynamely hydroxypropylcellulose, V11d-be. of relatively low detergency promoting ability :for .sodium kerylbenzene sulfonate. y f? f Theemcacy .of Athe addition of l0 kand 40 parts, respectively, of hydroxyethylcellulose iper ".100 parts of `sodium kerylbenzene sulfonate next led to vthelexamination of .the'detergent action of the complete .two component'system: sodium kerylbenzene sulfonate-hydroxyethylcellulose. As a result or" this'. latter investigation, it was dis.- covered .that theres a well dened zoneof the proportions of .thesetwo components, where the desired, andoutstanding .promotion .of .detergent properties l; are obtained.' This statement is Yfurther illustrated .by thecurve shown in the drawing;

As noted bythe it is a curve `showing the .relationship of the carbon soilremoval values in the two component system (sodium kerylbenzene vsulfonatehydroxyethylcellulose) overthe range. proportions of ingredients varying from 0 to Z100% sodium kerylbenzene sulfonate, and conversely from to 0% hydroxyethylcellulose. Test formulation mixtures of these `two ingredients over such range proportions, were made up and tested for `their ydetergent properties, according to the carbon soil removal test procedure hereinbe'fore described. These tests were conducted in distilled water at F. with a total concentration of ingredients equal vto 0.25%. The curve shown in thedrawing represents the per cent of standard soil removal values that were obtained over the 0 to `100%.range proportions of the two ingradients. The standard, or 100% value was of course the carbon soil removal value for the composition oonsisting entirely of-sodium kerylbenzene sulfonate alone with no hydroxyethylcellulose present.

As Ain previously described test results of compositions embodying. the'principle of our invention, theprecise identification of the ingredients are as follows:

Sodium kerylbenzene sulfonate:

Wyandotte Kreelon 4D Lot No. C-2687 M, manufactured by Wyandotte Chemicals Corporation, containing 58% NazSOr.

Hydroxyethylc ellulose Cellosize-WS, manufactured by Carbide & 'Carbon Chemical Corporation, having a `viscosity of 87 cps. land over 2 ldegrees of substitution of ethylene glycol groups per glucose unit of cellulose.A

Fromthe results shown in the drawing, it will .be .seen that as vlow as 1% hydroxyethylvcellulose eiects a detergency increase to 130% of standard. This 130% of standard detergency lincrease is maintained up rto `the proportion of 37% sodium kerylbenzene sulfonate and 63% hydroxyethylcellulose. Hence the area bounded by the 130% 'standard soil removal line and the portion of the curve above it, is denoted as zone vof 30% promotion.y "-Ihus the vcombination of l-63% of hydroxyethylcellulose lwith sodium kerylbenzene sulfonate, produces 130% or greater of standard detergent value.

Similarly, from Fig. 1, it will be noted the zone of 50% promotion is bounded by the vertical ordinates corresponding to 5-57% of hydroxyethylcellulose and the of standard soil removal value by the horizontal ordinate. This means that a formulation containing une legend vto this drawing,

7 43-95% sodium kerylbenzene sulfonate and -57% hydroxyethylcellulose possesses a carbon soil removalvalue of 150% of standard or greater. And as previously'pointed out in the specication, this value of 150% of standard is equal to or better than that of high grade soap in the washing of cotton fabrics.

XVe have also discovered that hydroxyethylcellulose when combined with sodium carboxymethylcellulose. will given an equally efcacious detergency promotion of sodium kerylbenzene sulfonate. Thus, a mixture containing equal parts of hydroxyethylcellulose and sodium carboxymethylcellulose was mixed in the ratio of parts by weight with 100 parts of sodium kerylbenzene sulfonate (58% NazSOi). On making this composition up into a solution in distilled water of 0.25% by weight of concentration on the basis of sodium kerylbenzene sulfonate present, a carbon soil removal of 174% of standard was obtained. Thiscompared with values of 164% of standard where hydroxyethylcellulose alone was used and 159% of standard vwhere sodium carboxymethylcellulose was used (10 parts of cellulose ether per 100 parts of sodium kerylbenzene sulfonate in each case). It will thus be seen that this mixture of equal parts of these two particular cellulose ethers resulted in a synergistic effect inasmuch as the detergency, or carbon soil removal value was greater than the highest value that could be obtained from equivalent amounts of either one of them.

The compositions of our invention also embrace the alkaline salt built type wherein such inorganic salts or builders as the sodium carbonates: sodium carbonate, sodium bicarbonate, modied soda (a combination of the iirst two); the sodium phosphates (ortho, meta, pyro, and tripolyphosphates, and including those polyphosphates of the calciumand magnesium ion sequestering type whose NazO/PzOs ratio ranges from 1:1 to 12/3:1-) sodium silicates (meta, orthosilicates and water glasses) and sodium borates (borax and metaborate) are added. Such additions of inorganic alkaline salts are made in proportions of up to 65% by weight of the total composition.

Thus, the promoted and built formulations of our invention have the following range proportions of ingredients:

Per cent Sodium alkylaryl sulfonate 25-90 Hydroxyethylcellulose 1-63 Inorganic alkaline salt 1-65 In the above formulations, where the inorganic alkaline salt or builder imparts an alkalinity of above 10 pH to the aqueous washing solution, the hydroxyethylcellulose, as hereinabove mentioned, may have a degree of substitution of 1-2 glycol residue groups per glucose unit of cellulose.

The relatively highproportion of alkaline salt building thatis tolerated by such formulations is illustrated lby the following tabulated results, where the amount of builder was present in amounts up to, and approaching the 65% maxi- 8 mum limit, while, even then a 30% or greater detergencyimprovement was obtained:

Other modes of applying the principle of our invention, in addition to the one hereinabove described and illustrated in detail, may be employed, provided the elements stated by any of the following claims or the equivalent of such elements be utilized.

We, therefore, particularly point out and distinctly claim as our invention and discovery:

1. A synthetic detergent composition consisting essentially of sodium alkylbenzenesulfonate, whose alkyl group contains 9-16 carbon atoms and 1-63% by 'weight of hydroxyethylcellulose.

2. The composition as in claim 1, but wherein the hydroxyethylcellulose is present in the amount of 5-57% by weight.

3. The composition as in claim 2 where the hydroxyethylcellulose contains 2-3 glycol residues pel` glucose unit of cellulose.

4. The composition as in claim 1, but wherein there is added up to by weight of the total resultant composition `of an inorganic alkaline salt builder selected from the group consisting of sodium carbonate, sodium bicarbonate, modiiled soda, sodium ortho, meta, pyro, tripolyphosphates, sodium phosphates of the calciumand magnesium ion sequestering type having an Na2O/P2O5 ratio in the range of 1:1 to l%:1, sodium'meta, orthosilicates, water glass, borax and sodium borate.

LESLIE R. BACON. CLIFTON E. SMITH. THOMAS H. VAUGHN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,202,741 Maxwell May 28, 1940 2,298,651 Samaros et al Oct. 13, 1942 2,298,696 Harris Oct. 13, 1942 2,335,194 Nsslein Nov. 23, 1943 2,347,336 Seyferth Apr. 5, 1944 2,373,863 Vitalis Apr. 7, 1945 FOREIGN PATENTS Number Country Date 805,718 France Nov. 27, 1936 265,688 Great Britain May 13, 1937 718,339 Germany Feb. 19, 1942 

1. A SYNTHETIC DETERGENT COMPOSITION CONSISTING ESSENTIALLY OF SODIUM ALKYLBENZENESULFONATE, WHOSE ALKYL GROUP CONTAINS 9-16 CARBON ATOMS AND 1-63% BY WEIGHT OF HYDROXYETHYLCELLULOSE. 